Abstract : Westinghose Electric Corporation has partially reduced troublesome cracking in thermocouples of pure GeTe by the addition of approximately 10% TlBiTe2. General Atomic division of General Dynamics Corporation found that barium doping improved the thermoelectric performance of cerium sulfide. Chrysler Corporation, in their investigation of compounds of high atomic weight refractory metals (Hf, Ta, W, Re) with IV B(Ge), V B(As, Sb, Bi),and VI B(Se, Te) elements, found that these are not promising as thermoelectric materials. Similarly, investigation of thorium and uranium sulfides, selenides, and tellurides by Electro-Optical Systems, Inc., did not appear promising. Thermal instability has thus far limited MoTe2 and WTe2 alloys to 400 to 500 C at the most. An investigation by the U.S. Naval Engineering Experiment Station of twenty commercial n-type lead tellurides indicated that no improvement in material efficiency should be expected by changing cylindrical-shaped elements to truncated conical shapes. (Author)